Cutter-head.



J. H. BURKE.

CUTTER. HEAD. APPL'IOATION FILED MAR. 13, 1912.

Patented July 23, 1912.

UNITED sTATE s PATENT OFFICE.

JOSEPH I-I. BURKE, 0E PORTLAND, MAINE, ASSIGNOR To THE BURKE 00., orPORT- LAND, MAINE, A coRroRATIoN or MAINE.

CUTTER- I-IEAD.

Specification of Letters Patent. 7 Patented J ul y 23,1912.

Application filed March 13, 1912. Serial No. 683,553.

1'0 all whom it may concern:

Be it known that I, JOSEPH H. BURKE, of Portland, in the county ofCumberland and State of Maine, have invented certain new and usefulImprovements in Cutter-Heads, of which the following is a specification.

My invention relates to a cutter head and it relates particularly to animproved construction of the cutter head shown and described in myUnited States Letters Patent dated Nov. 1, 1910, No. 974,234. In thatpatent I showed and described a cutter head made up of an arbor on whichwas a pair of segmental cutter blades, that is, blades having oppositetoothed cutting edges each occupying a segment of a circle approximately90 degrees each. One of the cutter blades was a flat blade and the otherwas bent or offset so that when the two were placed face to face on thearbor their cutting edges would travel normally in the same plane.

In this cutter head the offset blade was held,

in a fixed position next to the collar and the fiat blade was madeadjustable toward and from the oifset blade by means of a screw threadedbushing which was contained in a screw threaded opening in the center ofthe fiat blade. By means of this construction I was able to cut groovesof any width ranging from the thickness of a single blade up to doublesuch thickness by moving the flat blade in or out so that the path ofits: cutting edges overlapped the path of the cutting edges of theoffset blade more or less. Thus at the inner position both paths wereexactly in line and in the outer position they ran side by side with nospace between them. This arrangement answered every purpose so long as Ionly wanted a groove within the limits spoken of, but if I wanted awider groove there was no practical way of making it while getting theadvantage of the fine adjustment which the movable blade otherwise gaveme. If an extra blade was inserted between the two blades my flat movable blade came against the flat inserted blade which latter overlappedthe offset blade. Thus when I attempted to move my flat blade I formed aspace between it and the auxiliary fiat blade and'while I could build upthe cutter head to form any stand ard groove, I lost the benefit of thefine adjustment which I had in narrow grooves using the two originalblades. This difficulty I found could be remedied by reversing thearrangement of my blades and making the flat one the fixed blade and theoffset one the movable blade. WVhen this was done I could insert anynumber of auxiliary blades and always be able to vary the width of thegroove an amount equal to the thickness of the offset blade as will behereafter more clearly shown.

I have illustrated my invention by means of the accompanying drawing, inwhich is shown an improved cutter head constructed according to mypresent invention and includingone auxiliary cutter blade.

In the drawing, Figure 1 is a section on the line 00 m of Fig. 2, andFig. 2 is a central vertical section on Fig. 1.

The arbor a is provided with the usual flange a and one or more of thefixed segmental cutter blades are slipped onto the arbor and held byfriction against the flange a. As here shown, the regular fixed cutterblade crests against the flange a. It has expanded ends and a contractedcenter with suitable teeth on the segmental ends and it is shown with aflat or plane surface throughout. An auxiliary cutter blade of suitablethickness is slipped on the arbor next to the blade 0. It is so formedthat its teeth will travel'in a path which will supplement the teeth ofthe blade 0 so that thetwo will cut a single groove. As many of theseauxiliary cutter blades are used as are necessary to make the width ofthe groove desired. Limited variations in the width of the groove areproduced by a movable cutter blade with an offset sothat its cuttingedges may travel in the same path as those of the adjacent fixed cutterblade. As here shown, the cutter blade 0 is bent or offset so that itscutting edges will run normally in the path of the cutting edges of theauxiliary cutter blade d. When at its inner position it runs entirely inthe path of the cutting edges of the cutter d and as it is moved outwardit overlaps the cutter blade cl less and less increasing the width ofthe groove cut by the cutters c and d until at its outer position itswhole thickness is added to the thickness of the other blades. Thus ifthe blades 0 and Z aggregate J inch in thickness and the blade 6 isinch, the groove may be varied from 1} inch when the blade 6 is in itsinner position to 5- inch when at its outer position.

The adjustment of the blade 6 is effected evident that the movable blademay be used in conjunction. with the fixed blade 0 alone or with anynumber of auxiliary blades. I thus get in my present invention, a cutterhead which may not only be varied according to the thickness of the twooriginal overlapping blades but I am enabled to build up the head to anydesired thickness varying the exact Width of the produced groove withinthe limits of the thickness of the offset blade which would commonly beinch.

My present cutter head thus has a far greater range of usefulness thanmy former device which had a very limited range of adjustment.

I claim;

1. In a cutter head, the combination of an arbor, a fixed cutter bladeon said arbor, said cutter having opposite segmental cutting edges and amovable cutter blade on said arbor bent or oifsetso that its cuttingedges may travel in the same path as the cutting edges of said fixedcutter blade, and means for adjusting said movable cutter blade awayfrom and toward said fixed cutter blade.

2. In a cutter head, the combination of an.

arbor, a plurality of fixed cutter blades on said arbor, the outer bladebeing segmental, said blades being formed to out a continuous groove, amovable segmental cutting blade on said arbor bent or offset so that itscutting edges may travel in the path of the cutting edges of theadjacent fixed cutter blade, and means for adjusting said movable cutterblade from and toward said adjacent fixed cutter blade.

3. In a cutter head the combination of an arbor, a fiat segmental cutterblade on said arbor, a movable cutter blade on said arbor bent or ottsetso that its cutting edges may travel in the same path as the cuttingedges of said flat cutter blade and means for adjusting said movablecutter blade from and toward said fiat cutter blade.

4. In a cutter head, the combination of an arbor, a flat segmentalcutter blade on said arbor, a movable cutter on said arbor bent oroitset so that its cutting edges may travel in the same path as thecutting edges of said flat cutter blade, and having a central screwthreaded opening and a screw threaded bushing in said opening adapted toimpinge on said flat cutter blade and clamping means for securing theparts in place.

5. In a cutter head, the combination of an arbor, a plurality of fixedcutter blades on said arbor formed to travel in the same groove, theouter blade being segmental, a movable segmental cutter blade on saidarbor, said movable cutter blade and its adjacent fixed cutter bladebeing so formed that their cutting edges may travel in the same planeand means for adjusting said movable cutter blade from and toward thefixed blade.

In testimony whereof I have aflixed my signature, in presence of twowitnesses.

JOSEPH H. BURKE.

WVitnesses:

S. W. BATES, C. B. CREIGHTON.

copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents. Washington, D. C.

